The Brain Is Essential – But Don’t Call It Essentialist!

Last week I dug into a series of stories that hit home how our views of mental function and health are changing, though there is still quite some way to go. These stories show how our understanding of brain function, people’s daily lives, and important social and cultural considerations mesh together. Rather than our old essentialist approach to the brain, where it was made into the biological mediator of difference, we have an emerging view that is critical and engaged with people’s lives, while also providing us important new insights into the role of neural function in daily function.

The question of variation, rather than difference, and how we understand that is a core scientific, methodological, and political aspect of this type of work. Essentialism and innate causes are not tenable starting positions for neuroanthropology.

In the interminable sex differences debate it always seems to be those who are critical of scientific claims of essential differences who are accused of allowing political desires to blinker them to the facts of the case… [For example], admonishments [about] the agenda-driven feminist who requires everyone to ignore what does not fit her ideology; and the detached spokesperson of science…

While a review of my book by The Essential Difference author and Cambridge psychologist Simon Baron-Cohen generously acknowledged its scholarship, the instantly recognizable stereotype was nonetheless lurking in all its unalluring glory: I was “strident”; in pursuit of a “barely veiled agenda”; and guilty of the “mistaken blurring of science with politics”…

The people detached from science are rather those arguing for an essentialist position. They fail to acknowledge the limits of science, and to look closely at what the data and methods actually say.

Again and again I argue that – because of under-acknowledgment of social factors, spurious results, poor methodologies, and untested assumptions – the evidence scientists and commentators provide as support for essentialist claims is simply not as strong as they seem to think…

What about claims of sex differences in the brain, sometimes speculatively linked to aptitude in science and maths? Small sample sizes, noisy data, publication bias, and teething problems with statistical analysis techniques leave this literature littered with spurious findings of sex differences.

Fine argues forcefully that we need to leave the stereotypes of “straw feminist” and “value-free scientist” behind. Science involves politics and ideologies, from assumptions made to presentation of results in public. A more direct recognition of political and social thought as part of science itself is needed, even when trying to hew to the ideals of what counts as good hypothesis testing and valid evidence.

Louis Menand and the Trilogy of Psychiatry

Louis Menand produces just this sort of example when he discusses science, psychiatry and science in the New Yorker article Head Case. His main case study is depression, and a suite of books with critical takes on depression as a biological disease, as needing pharmacological treatment, and so forth. But he also goes back to the case of tranquilizers, and considering psychiatry’s history with Freud, pharmacotherapy, the placebo effect, and the role of the Diagnostic and Statistic Manual.

Here’s a taste of one book, Gary Greenberg’s Manufacturing Depression.

Greenberg basically regards the pathologizing of melancholy and despair, and the invention of pills designed to relieve people of those feelings, as a vast capitalist conspiracy to paste a big smiley face over a world that we have good reason to feel sick about. The aim of the conspiracy is to convince us that it’s all in our heads, or, specifically, in our brains—that our unhappiness is a chemical problem, not an existential one. Greenberg is critical of psychopharmacology, but he is even more critical of cognitive-behavioral therapy, or C.B.T., a form of talk therapy that helps patients build coping strategies, and does not rely on medication. He calls C.B.T. “a method of indoctrination into the pieties of American optimism, an ideology as much as a medical treatment.”

Greenberg is repeating a common criticism of contemporary psychiatry, which is that the profession is creating ever more expansive criteria for mental illness that end up labelling as sick people who are just different—a phenomenon that has consequences for the insurance system, the justice system, the administration of social welfare, and the cost of health care.

Menand uses his review of psychiatry, science, and history to make a crucial point about the field, and about our understanding of mental illness.

Mental disorders sit at the intersection of three distinct fields. They are biological conditions, since they correspond to changes in the body. They are also psychological conditions, since they are experienced cognitively and emotionally—they are part of our conscious life. And they have moral significance, since they involve us in matters such as personal agency and responsibility, social norms and values, and character, and these all vary as cultures vary.

Many people today are infatuated with the biological determinants of things. They find compelling the idea that moods, tastes, preferences, and behaviors can be explained by genes, or by natural selection, or by brain amines (even though these explanations are almost always circular: if we do x, it must be because we have been selected to do x). People like to be able to say, I’m just an organism, and my depression is just a chemical thing, so, of the three ways of considering my condition, I choose the biological. People do say this. The question to ask them is, Who is the “I” that is making this choice? Is that your biology talking, too?

The decision to handle mental conditions biologically is as moral a decision as any other. It is a time-honored one, too.

As Menand points out, the position of people dealing with depression has consistently been, Take the meds. Menand doesn’t dwell at much length about the patient’s perspective, or how families cope with mental illness. But he does stress how questions of different, normality, and daily experience consistently arise in psychiatry, and cannot be resolved by an essentialist biological approach. In other words, patterns of experience, rather than questions about essential differences, can yield a better understanding of the reality of neurological function and disease.

The contrasting descriptions of Henry’s delusional acts were striking. For the father, dealing with schizophrenia was haunting and difficult, full of fear and hardship.

Patrick (father): You know, this is a terrifying cruel illness that affects millions of people and many more millions of their families. And it — and it goes on for such a long period. It doesn’t really stop. It sort of beats you down. So, you know, things have got better in recent years but initially Henry was continually disappearing.

You know, once he spent two days naked in the snow under a tree. We couldn’t find him. The local police were looking for him. This happened again and again. And — but, you know, fortunately my wife and I were together doing this. I mean, I pity any individual person who tries to cope with this all on their own. I think that would destroy people.

For the son, it was liberating, a positive experience, even to this day.

Henry (son): I felt the trees sort of ushering me to take my clothes off, so I took my clothes off. And the sound of the tree and the tree started moving and the — you know, I could feel it pushing against my fingertips and (unintelligible). And then it was marvelous and I was so sheltered from the snow a bit because the tree was sort of, you know, above my head. And I saw lights flickering in the distance. It was — it wasn’t quite, you know, me being in a snowdrift. I was sort of protected…

If you gave me a time machine and I went back to square one I’d probably do the same thing, you know. I mean, I learned a lot from going back to the wild ways.

One could take an essentialist position, and say Henry Cockburn suffers from a brain disease. But it would miss the negotiation between father and son, and the meaning of the illness for both of them.

Coda – One

Where does all this leave us?

Let me return to the beginning, to Cordelia Fine and how we can think better about science, neural function, and human difference.

The essentialist view of the brain is rapidly falling by the wayside. It is not just the recognition of neuroplasticity, and how experience and use can shape how the brain fires and wires together. Today, how we think about what parts of the brain do has changed – the essentialist view of innate modules, as well as our projection of human categories onto the brain, has come largely undone in the science.

The Amygdala – It’s Not Just fear Anymore

One of my favorite recent examples is of the amygdala. Before, this was the fear center of the brain, our view that one part of the brain mentioned this one basic emotion (crucial for survival, and so of course hard-wired…). But today, the amygdala is now seen to mediate reward, attention, and sensory processing.
Susan Guides, with the piece Cerebral Delights in Science News, covers much of this new research. Here is how she summarizes this changing view of one of the iconic structures of the brain.

It turns out that the amygdala helps shape behavior in response to all sorts of stimuli, bad and good. It plays a role not only in aversion to fright, but also in pursuit of pleasure.

Studies of the brain’s anatomy reveal good reasons for the amygdala’s power: It is very well connected. In humans and other primates, the amygdala is linked through a complex network of cells to brain regions involved in all five senses. Signals about everything you encounter are passed from the brain’s sensory processing areas directly to the amygdala. And the amygdala shares elaborate communications channels with the prefrontal cortex — the brain’s control center for planning and decision making.

Its strategic location allows the amygdala to act as a spotlight, calling attention to sensory input that is new, exciting and important. In this way, it helps predict the timing and location of potential dangers, helping you dodge many of the things you dread. But those same connections also help you acquire the good things in life, by identifying and assessing rewards such as food, sex and other delights.

Beyond the Phrenology of Neuroimaging

On the methods side, neuroimaging is also revealing itself to not be the “localization” demon many had hoped for. Rather, neuroimaging is a technical and methodological approach, not a revelation machine.

The Neurocritic, in the piece Phrenology, Then and Now, makes this point explicit. At its worst, neuroimaging has been used as a new phrenology, mapping mental faculties onto the brain just like phrenology did with skull anatomy.

Gall’s ambition and vanity are now ‘activation for judgment about self versus others’, localized to medial prefrontal cortex. Friendly attachment/fidelity have been transformed into ‘viewing a friend versus viewing a stranger’, associated with right temporoparietal cortex.

The mapping gives us a sense of biological reality – but it is a sense that only we see. As the Neurocritic says, we are still after localization, whether in specific spots (the older view) to discrete networks (the view today). We are still after that difference that makes a difference – at least in our ability to argue about what the brain reveals.

Killing Curiosity

Bradley Voytek captures this well when he writes about how to spot “neuro nonsense” statements in his post How to Be a Neuroscientist. He opens by discussing a recent Quora discussion on the neurobiological basis of curiosity, and the top answer at that time – the striatum lights up like “an inferno of activity” in imaging of curiosity.
What’s wrong with that view?

1. The question is phrased in such a way that it presumes that “curiosity” is a singular thing.

2. The question presumes that a complex behavior or emotion can be localized to a brain region or regions. There are several philosophical pitfalls packaged into the answer, such as the ontological commitment to the narrative of cognitive neuroscience and the cerebral localization of function.

Brad highlights the importance of what is meant by “function” before we go about localizing it. As work on the amygdala shows, our concept of fear, in particular the idea that we must have innate reactions to danger hard-wired into a specific circuit, is just not how the brain works.

As that long phrase shows – innate reactions to danger hard-wired into specific circuits – we package a lot into our ideas about function. Those ideas about “function” do not match up well with functional neuroanatomy.

Young and colleagues (2000) noted that for a given function to be localizable that function “must be capable of being considered both structurally and functionally discrete”; a property that the brain is incapable of assuming due to the intricate, large-scale neuronal interconnectivity.

Mechanisms Matter

Where does all this leave us? How can we draw fruitfully on neuroscience?

I like a recent Scicurious post on Stress, Dieting, and the Changing. Our folk model of weight loss – that if you put your mind to it, like any good person with self-control, you can lose weight and keep it off – just doesn’t match up with the reality of obesity science. The vast majority of diets fail.

Scicurious turns that into a question: Why do diets fail?

She first looks at recent work with mice, where researchers made mice mimic humans on a diet. Dieting in the mice lead to changes in stress hormone expression in the brain, particular through DNA methylation in corticotropin releasing factor in the bed nucleus of the stria terminalis (yup, that’s a mouthful).

The take-home point? Dieting can lead to changes in stress expression in the brain, even after individuals have returned to a normal diet.

The really crazy thing about this change in methylation is that it’s very long LASTING. Cells don’t methylate lightly, and once they do, the change can go on for years…

When the scientists looked at mice that had diets compared to those that didn’t, they saw that the methylation of the CRF gene was decreased, both in dieting mice and in mice that had previous had diets but were now being refed. This suggests that the mice that had had diets retain the changes in stress hormone expression that they had during diets. The pounds may not stay off, but the methylation will stick with you…

The take home message is this: Dieting not only causes you to lose weight, it interacts with the way your body deals with stress, and makes it more likely for you to eat more when times of stress come around again. Over the long run, this could result in…weight gain, screwing over all you worked for.

Here, rather than a localization study, Scicurious is getting at potential mechanisms that might underlie an empirical observation. If the folk model fails – self control in a diet leads to long-term weight loss – then a fruitful search for an understanding of the mechanisms involved is useful.

Rather than assuming that calorie restriction means “starvation” in evolutionary terms, leading to a search for food to stave off death, a close examination of data leads to a better biological hypothesis about what might be happening.

And rather than assuming that self-control is some autonomous function of the mind, surely one that could be mapped onto the prefrontal cortices, this approach gets at how one aspect of behavioral biology – stress reactions to calorie restriction – can lead to long-term changes in one component of a mouse brain.

It’s certainly not some essential difference, but it is an intriguing result. The move from this research to humans is complex and messy, as Scicurious’ post on Eating, Stress, Reward and Obesity and my long-ago post on Comfort Food and Social Stress show in their different ways. (For more, there is a whole selection of Food, Obesity, and Eating posts at the old Neuroanthropology – including this one on Calories Not Diets.) But starting with what the research actually shows us, complete with questioning and critique a la Scicurious and Cordelia Fine, can help us navigate better than an essentialist approach to brain and behavior.

Coda – Two

A grounding in the mechanisms revealed by basic research, as well as an understanding of the networked and plastic nature of the brain, brings us a long-way from the “we’re going to spot the difference” approach.

Rather than looking to the brain to justify our thoughts about the world, we can look for the brain to offer up innovative results that make us rethink our assumptions and offer new hypotheses to explore, whether we work in the neurosciences, in psychology, or in anthropology.

5 Responses to The Brain Is Essential – But Don’t Call It Essentialist!

Daniel writes: “In other words, patterns of experience, rather than questions about essential differences, can yield a better understanding of the reality of neurological function and disease”
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I would say both experience and essential differences blend, but ceding primacy to one or the other would be sort of, uh, essentialist, wouldn’t it?

In a similar vein, discovering increasingly complex and subtle functions performed by the amygdala doesn’t meant that the prior perspective–the amygdala as an essential element in the fear cycle–has been retracted, it’s just been extended, seems to me.

I’m with you about the extent of “neuro nonsense” out there, but lest we forget, a lot of it grew out of an inevitable movement away from the “social nonsense” that characterized the world of the blank-slate mind for so long. A bit of overcorrection seems natural and forgivable, in a historical sense.

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Neuroanthropology. Sometimes it’s straight-up neuroscience, sometimes it’s all anthropology, most of the time it’s somewhere in the middle. Greg is the cultural guy, now interested in bio stuff. Daniel is the bio guy, now interested in cultural stuff. Or, to say it differently, Greg does capoiera, mixed martial arts, and rugby. Daniel does alcohol, drugs, and video games. Two very different styles of recreation.